update-containers kept LOCAL_BUILD, a hand-written list of services whose
images are built on the machine, so it would not try to pull them. The
compose files already say this. A service with a build: stanza names a
local image, and there is nothing in a registry to pull.
images_for now drops the image of any compose service that has a build:
stanza. Those services resolve no images, and the run skips them without a
log line. The list, and the app names it carried, are gone. On the VPS,
--list resolves the same images as before for every other service.